Hi Martin,

> Problems appear when I use primitive ints in primary keys for my
> objects. When a referenced object has a 0 key "pf.get(object)" returns
> null and not the object referenced by the 0 key.
> When I use Integer objects as IDs I dont have any trouble... can anyone
> tell me why this happens?

This is expected behavior. The problem with primitive types is that they never represent 'null'. So when represents a primitive FK/PK null? When is a reference removed when FK is primitive? Assume you have a reference from A to B and the primitive PK of B is 0 (thus FK in A is 0), how can you reject the reference? The FK in A is already 0?
OJB use the default value of primitive PK,FK fields ('0') as 'null' representation. Thus if you use primitive fields as PK, all values should be != 0.
This is only true for primitive PK/FK fields. All other fields have 'normal' behavior.


regards,
Armin


Martin I. Levi wrote:
Hi!

I have a doubt related to PersistentFields and object mappings...
here i go:

I obtain a PersistentField from an object in this way:
-----------------------code starts here---------------------------------

private void loadFieldValues(BaseBusinessObject object)
throws MetadataException
{
Class attributeType = object.getClass();
MetadataManager mm = MetadataManager.getInstance();
DescriptorRepository dr = mm.copyOfGlobalRepository();
ClassDescriptor cld = dr.getDescriptorFor(attributeType);
FieldDescriptor[] fields = cld.getAllRwFields();


for (int i = 0; i < fields.length; i++)
{
//the code inside this "for" shows every field from
//(this) object and it works great so i omit it.
}

Vector references = cld.getObjectReferenceDescriptors();

//the following for creates a recursion
//to show every referenced object
//from this and the following referenced objects, etc.

for (int i = 0; i < references.size(); i++)
{
ObjectReferenceDescriptor reference =
(ObjectReferenceDescriptor) references.get(i);
System.out.println("-------------- " +
reference.getAttributeName()
+ " -------------");
String attributeName = reference.getAttributeName();
PersistentField pf =
PersistentFieldFactory.createPersistentField(attributeType,attributeName);
BaseBusinessObject objReference = (BaseBusinessObject)
pf.get(object); loadFieldValues(objReference); //recursive call!
}


}
-----------------------code ends here---------------------------------

Problems appear when I use primitive ints in primary keys for my
objects. When a referenced object has a 0 key "pf.get(object)" returns
null and not the object referenced by the 0 key.
When I use Integer objects as IDs I dont have any trouble... can anyone
tell me why this happens?

Thanks!


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